A StatisticsTypeFactory can create a statistic of three numeric types:
int, long, and double. A
statistic (StatisticDescriptor) can either be a
gauge meaning that its value can increase and decrease or a
counter meaning that its value is strictly increasing.
Marking a statistic as a counter allows statistic display tools
to properly display a statistics whose value "wraps around" (that
is, exceeds its maximum value).

The following code is an example of how to create a type using XML.
In this example the type has two stats whose values always increase: